Machine tools are as a rule program-controlled in that machining operations which are to be performed on a workpiece proceed under program control. To generate a relative motion between the tool and the workpiece, a plurality of NC (numerically controlled actuators) axes are provided. For example, a grinding head is supported on a suitable linear guide, which in turn is provided with an NC drive mechanism, or machine controlled actuator. Actuating one or more such acuators creates a positioning motion. In grinding spiral grooves on drilling tools, for instance, a plurality of motion components must be superimposed in order to achieve a suitable relative motion between the workpiece and the tool.
Numerically controlled machine tools, and control programs for them, are known. European Patent Disclosure EP 0 530 364 A1, for example, discloses an interactive numerical control that produces a display of a workpiece on a monitor on the basis of existing NC data. An interactive variation of the NC data can be displayed directly. Effects of data changes are thus made immediately visible. The system includes storage means, calculation means, display means and input means. From the display of the machining process on a monitor, the NC data can be corrected directly on the screen.
Programming NC machines demands certain skills, both in the programming language used and in terms of the special conditions involved in machining certain surfaces of the workpiece.